SPRAY NOZZLE FOR AN INHALATION DEVICE

Abstract

The invention relates to the field of inhalation devices for liquids. In particular, the invention relates to a nebulizing nozzle to be used in such an inhalation device, as well as a method for fabrication of such a nozzle. A nozzle for an inhalation device for nebulizing a liquid into a respirable aerosol has a nozzle body (1) which has a front end (1B) and which comprises at least two ejection channels (2, 2′), each channel (2, 2′) having an channel exit (2A, 2A′), wherein the ejection channels (2, 2′) are arranged such as to eject liquid along respective ejection trajectories which intersect with one another at a collision point. The nozzle is characterized in that at least one recess (3) is provided at the front end (1B) in which the channel exits (2A, 2A′) are positioned. Disclosed is also a method for the fabrication of a nozzle body as defined above, use of such a nozzle in an inhalation device for nebulizing a liquid, and an inhalation device for nebulizing a liquid into a respirable aerosol, comprising such a nozzle.

Claims

1. Nozzle for an inhalation device for nebulizing a liquid into a respirable aerosol, with a nozzle body which has a front end and which comprises at least two ejection channels, each channel having an channel exit, wherein the ejection channels are arranged such as to eject liquid along respective ejection trajectories which intersect with one another at a collision point, wherein at least one recess is provided at the front end in which at least two of the channel exits are positioned, wherein the nozzle body has a flat side, with the at least two liquid channels being entrenched with a defined depth on said flat side, wherein further, a lid is provided that covers the at least two channels, and which has a front end that is, in a view perpendicular to a longitudinal axis of the nozzle body, congruent with the front end of the nozzle body, and wherein said recess has a first depth which is larger than the depth of said at least two channels.

2. Nozzle according to claim 1, wherein at least two recesses are provided, and wherein in each of the two recesses only one channel exit is located.

3. Nozzle according to claim 1, wherein the nozzle body is a monolithic structure.

4. Nozzle according to claim 1, wherein the recess further has a portion which extends into the lid.

5. Nozzle according to claim 1, wherein said recess has, seen along longitudinal axis, an increasing depth and/or width, such that a sloping cross section is provided, being widest at the front end.

6. Nozzle according to claim 1, comprising a plurality of nozzle bodies.

7. Nozzle according to claim 6, wherein each nozzle body has its own recess.

8. Nozzle according to claim 6, wherein multiple nozzle bodies share a common recess.

9. Nozzle according to claim 1, wherein a side opposite to the flat side of one nozzle body serves as lid for an adjoining nozzle body.

10. Nozzle according to claim 4, wherein the lid provides the upper portion of the recess and wherein said portion runs from one side of the lid to the other side.

11. Nozzle according to claim 10, wherein the recess portion has the shape of a chamfer, with a channel-adjoining edge.

12. Method for the fabrication of a nozzle according to any of the preceding claims, the method comprising the steps of a) providing a nozzle body which has a front end and which comprises at least two ejection channels, each channel having an channel exit, wherein the ejection channels are arranged such as to eject liquid along respective ejection trajectories which intersect with one another at a collision point, wherein at least one recess is provided at the front end in which at least two of the channel exits are positioned, wherein the nozzle body has a flat side, with the at least two liquid channels being entrenched with a defined depth on said flat side, comprising the following steps: providing a wafer substrate; fabricating on one side of said substrate at least two liquid channels, said channels having a defined depth (D); fabricating a recess with a first depth which is larger than the depth of said at least two liquid channels in said one side of the body, said recess covering an end portion of the channels; separating said body from the substrate along a separation line which crosses said recess; such that at least two channel exits in said recess are obtained, wherein the distance between said channel exits remains unaffected by a possible angular or linear deviation of said separation line from an optimal separation line, and b) covering said nozzle body with a lid.

13. Method according to claim 12, wherein the lid covers the at least two channels, and which has a front end that is, in a view perpendicular to a longitudinal axis of the nozzle body, congruent with the front end of the nozzle body.

14. Method according to claim 12, wherein a pattern representing a plurality of nozzle bodies is batch fabricated in said wafer substrate, and wherein the separation line crosses all recesses.

15. Nozzle or method for the fabrication thereof according to claim 1, wherein the nozzle is batch-fabricated from a wafer substrate.

16. Nozzle or method for the fabrication thereof according to claim 15, wherein the wafer substrate comprises or consists of a brittle material such as silicon, glass, or ceramics.

17. Nozzle or method for the fabrication thereof according to claim 1, wherein the wafer substrate comprises or consists of polyether ether ketone (PEEK).

18. Nozzle according to claim 1, obtained or obtainable by a process according to claim 12.

19. Method of nebulizing a liquid into a respirable aerosol, the method comprising ejecting the liquid through the nozzle of claim 1, to produce the respirable aerosol.

20. Inhalation device for nebulizing a liquid into a respirable aerosol, comprising a nozzle according to claim 1.

Description

DESCRIPTION OF FIGURES

[0086] Subsequently, the invention is exemplified by aid of the following figures. Herein,

[0087] FIG. 1 shows a nozzle body according to the state of the art;

[0088] FIG. 2 shows a nozzle body as in FIG. 1, resulting from an angled separation line;

[0089] FIG. 3 shows a nozzle body having a recess;

[0090] FIG. 4 shows a nozzle body having a recess with an increased depth;

[0091] FIG. 5 shows a nozzle body as in FIG. 4 resulting from an offset separation line;

[0092] FIG. 6 shows a nozzle body as in FIG. 4 resulting from an angled separation line;

[0093] FIG. 7 shows a nozzle body as in FIG. 4, covered by a lid, with a single recess;

[0094] FIG. 8 shows a nozzle body covered by a lid, with two individual recesses;

[0095] FIG. 9 shows a nozzle body as in FIG. 4, covered by a lid, with a side-to-side recess;

[0096] FIG. 10 shows a cut view of a front portion of a nozzle;

[0097] FIG. 11 shows a nozzle with a recess that extends into a lid;

[0098] FIG. 12 shows a plurality of prior art nozzle bodies separated from a substrate along an optimal separation line;

[0099] FIG. 13 shows a plurality of prior art nozzle bodies when separated along an angled separation line;

[0100] FIG. 14 shows a plurality of nozzle bodies according to the invention before being separated along an offset separation line; and

[0101] FIG. 15 shows a plurality of nozzle bodies according to the invention before being separated along an angled separation line.

[0102] In FIG. 1, a nozzle body 1 according to the state of the art is schematically depicted. The nozzle body 1 has an overall shape of a rectangular cuboid. In a rear section, a collecting chamber is present; however, inlet ducts and the like are omitted in the drawing for the sake of clarity.

[0103] Two liquid channels 2, 2′ which are entrenched with a certain depth D are present on one flat side 1A of said nozzle body 1. Longitudinal axis X (thin dashed line) runs along the length of the nozzle body 1.

[0104] Each jet axis A, A′ (dash-dotted line) of each channel 2, 2′ crosses a front plane congruent with the front end 1B of the nozzle body 1. In this example, jet axis A, A′ is collinear with the respective channel axis (no reference numeral). In FIG. 1, depicting the state of the art, the so formed “front end channel exits” 2B, 2B′ are—in the absence of a recess—located in this front plane which is also the front end 1B.

[0105] During manufacture, the front end 1B may be generated by sawing, or otherwise separating, the nozzle body 1 from a larger unit (e.g. a wafer) along a separation line 5 (bold dashed line). In the example, this separation line 5 is collinear with an optimal separation line 5′. Therefore, the lateral distance Y of the front end channel exits 2B, 2B′, measured between their respective jet axes A, A′, is as initially designed or intended.

[0106] In FIG. 2, a prior art nozzle body as in FIG. 1, but resulting from a non-optimal, angled (with respect to the optimal separation line 5′) separation line 5, is depicted. In this figure, some of the already introduced reference numerals are omitted.

[0107] As can be seen, due to the angular deviation of the separation line 5 from the optimal separation line 5′, the lateral distance Y′ of the front end channel exits 2B, 2B′, again measured between their respective jet axes A, A′ at the respective front end channel exits 2B, 2B′, is not as initially designed (in this example, it is larger than intended). Since the front end channel exits 2B, 2B′ are now no longer located in the intended plane (front plane in FIG. 1), but in a plane that results from said angular deviation, their respective lengths (no reference numeral) also differ from each other. This might result in suboptimal nebulization. In the example, channel 2 is shorter than channel 2′.

[0108] As shown in FIG. 3, an exemplary nozzle body 1 has a recess 3. Recess 3 has a depth D′ which is, in this example, equal to the depth D of channels 2, 2′. As the channels 2, 2′, recess 3 is provided in said flat side 1A. It is located at the front end 1B of the nozzle body 1, as an indentation of the front end. Thus, recess 3 could be understood as encompassing the (now “virtual”) front end channel exits 2B, 2B′ (hatched areas) such that (“real”) channel exits 2A, 2A′ are provided that are set back with respect to said front end 1B at a certain offset 01.

[0109] As a result, any potential damages to the front end 1B resulting from separating, such as by mechanically sawing, the nozzle body 1 from a larger unit along the separation line 5′ which is, in this example, also the optimal separation line 5, do not affect the channel exits 2A, 2A′ since these are never touched by a sawing blade or any other separation tool. Thus, the quality of a liquid jet ejected from such channels during nebulization is also not affected. Even if the surface roughness of the front side 1B is increased due to faster sawing, this will not have a negative influence on the jet quality. Therefore, quicker and/or less costly separation techniques can be used for separating the nozzle body 1 from its substrate.

[0110] In FIG. 4, a nozzle body 1 having a recess 3 with an increased depth D′ is shown. In this way, a step is present at the exits 2A, 2A′ of the channels 2, 2′, said step being also precisely fabricable. In the example, each channel exit 2A, 2A′ (before adding a counterpart such as a lid) has three sides which can be designed to exhibit a high surface quality, namely the right and left side (defined by the width W′ of recess 3), as well as the bottom side (defined by the depth D′ of the recess 3). It should be pointed out that for a satisfying jet quality, in particular, the quality of the edges surrounding each channel exit 2A, 2A′ must be good; this is true for all embodiments. The advantage of this embodiment is that the liquid jet (not shown) which leaves a channel 2, 2′ does not come in contact with any other surfaces or edges which may have lower surface or edge quality, thus ensuring a high quality and reproducibility of nebulization.

[0111] FIG. 5 shows a nozzle body 1 as shown in FIG. 4, but in this case, nozzle body 1 was individualized along a separation line 5 which is spaced apart with an offset O2 from the optimal separation line 5′, lies in front of the nozzle body 1. As a result, front end 1B of the nozzle body 1 in FIG. 5 is parallel to the one in FIG. 4. Despite this difference, the exits 2A, 2A′ have the same, desired distance from each other as in the embodiment of FIG. 4. Thus, the position of the separation line 5 can vary in a certain range without affecting the relevant geometry of the nozzle body 1.

[0112] In FIG. 6, a nozzle body similar to the one of FIG. 4 is shown, but in the depicted case, nozzle body 1 was individualized along a separation line 5 which includes a pointed angle a with the optimal separation line 5′. However, again, this deviation does neither affect the length of the channels, nor the distance of their channel exits (respective reference numerals omitted), since recess 3 provides a “buffer” for imprecise orientation of the separation line 5.

[0113] Of course, recess 3 can also compensate the otherwise negative effects of a combination of an angular and offset deviation, as well as any other deviation, as long as the resulting cutting plane lies entirely within recess 3.

[0114] In FIG. 7, a nozzle body 1 is shown which is covered by a lid 4. The resulting nozzle comprises a single recess 3 which has a lower portion, located in the nozzle body 1, and an upper portion 3′ which is located in the lid 4. As can be seen, a circumferential step is present that surrounds both channel exits 2A, 2A′.

[0115] In contrast, in FIG. 8 shows another nozzle body 1 which may be made from a monolithic structure. Thus, a lid is not necessary. In this embodiment, two individual recesses 3 exist, each surrounding one channel exit 2A and 2A′, respectively. It is clear that an embodiment with two recesses is also possible if the nozzle body 1 is designed as shown e.g. in FIG. 7 with “open” channels 2, 2′ and a lid 4.

[0116] FIG. 9 shows an embodiment with a lid 4 that provides the upper portion 3′ of the recess 3, wherein said portion 3′ runs from one side of the lid 4 to the other side. The recess portion 3′ has the shape of a chamfer, with a channel-adjoining edge 6. As shown, preferably, said edge 6 is collinear with the respective edges of the channel exits 2A, 2A′. In this way, still, a circumferential step is provided around said exits 2A, 2A′.

[0117] An additional advantage of said embodiment is that, due to capillary effects, liquid which can accumulate during use of the nozzle around the exits 2A, 2A′ is transported away from the exits towards the sides of the nozzle. It is clear that neither the shown angles nor dimensions are drawn to scale; depending on physical parameters such as the viscosity of the liquid, other dimensions can be necessary in order to obtain an optimal result. It is also clear that the slope of the chamfer must be larger than the diameter of the jet in order to avoid collision of the jet with the wall of the portion 3′.

[0118] In FIG. 10, a cut view of a front portion of a nozzle, based on the embodiment of FIGS. 3 to 6, comprising the nozzle body 1 is shown. In this embodiment, a counterpart in the form of a lid 4 which serves as a cover was placed onto the one side 1A so as to close channels 2, 2′ (channel 2′ not visible). The cut view goes through the end portion of channel 2 which is therefore drawn without hatching.

[0119] Due to recess 3, the channel exit 2A is offset at distance 01 from front end 1B. As can be seen, front end 4B of lid 4 is, in a view perpendicular to a longitudinal axis X (from above in FIG. 7, parallel to the drawing plane), congruent with the front end 1B of the nozzle body 1.

[0120] Although non-congruent embodiments are also possible, the embodiment of FIG. 10 is particularly advantageous because it can be achieved by firstly bonding substrate containing a plurality of nozzle bodies and another substrate containing a plurality of lids 4 to each other, and then by separating the initially semi-finished nozzle along a separation line which is perpendicular to the drawing plane in FIG. 10 from its neighboring nozzle (not depicted), such that individualized nozzles are obtained, each comprising a nozzle body and a lid bonded to the same. Since lid substrate and nozzle body substrate are cut in the same workstep, the congruency is produced automatically. An advantage is the symmetric result, since top and bottom sides in front of the channel exits 2A, 2A′ are essentially mirror-inverted with one another. Thus, the liquid jet will not deviate in either of these directions.

[0121] In FIG. 11, a further embodiment of a nozzle comprising a nozzle body 1 and a lid 4 is shown, again with a recess 3 which has a portion 3′ which extends into the lid 4, similar to the embodiment shown in FIG. 7. The lower portion of recess 3 is located in nozzle body 1, also enclosing channel 2, whereas upper portion 3′ is located in lid 4. In this embodiment, portion 3′ is, with respect to a nozzle central plane P (dotted line) which is parallel to said one side 1A, symmetric to the lower portion of recess 3 of nozzle body 1.

[0122] Further, and contrary to the situation shown in FIG. 10, in this embodiment, recess 3 has, seen from the channel exits 2A, 2A′, an increasing depth D′ (measured in vertical direction in FIG. 11), thus enlarging towards the front end 1B, 4B. Optionally, the width may also increase along the same direction. In this way, the shown sloping cross section is provided, being largest at the respective front end 1B, 4B. Such a sloping cross section allows for a particularly smooth transition from the channel exits 2A, 2A′ to the recess walls, providing a “bell-like” region where the liquid jet (not shown) leaves each channel exit. As a result, the jet quality is increased.

[0123] FIG. 12 shows schematically a plurality of nozzle bodies from the known art which are just separated from a substrate (not shown) along their respective front ends (reference numerals omitted). The optimal separation line 5′ is indicated by the dashed line. As a result, all nozzle bodies are identical; in particular, the distances between the channel exits are identical for all nozzle bodies.

[0124] However, if the nozzle bodies are separated along separation line 5, as depicted in FIG. 13, an angular deviation exists which results in a variation of the lateral distances Y′ of the channel exits, which is clearly undesired. Also, the respective lengths of both channels of one nozzle body are also slightly different (each left channel is shorter than the respective right channel).

[0125] This disadvantage can effectively be avoided by a nozzle having a recess as described above.

[0126] As can be seen in FIG. 14, an offset between optimal separation line 5′ and real separation line 5 does not affect the channel exit positions or channel lengths (reference numerals omitted), unless the offset O1 is larger than the length of the recess 3 (offset O2).

[0127] Also, as can be seen in FIG. 15, an angular deviation of separation line 5 does not affect the positions or lengths of the channels exits, as long as the separation line 5 crosses the recess 3 of each nozzle body.

[0128] The following is a list of numbered items comprised by the present invention: [0129] 1. Nozzle for an inhalation device for nebulizing a liquid into a respirable aerosol, with a nozzle body (1) which has a front end (1B) and which comprises at least two ejection channels (2, 2′), each channel (2, 2′) having an channel exit (2A, 2A′), wherein the ejection channels (2, 2′) are arranged such as to eject liquid along respective ejection trajectories which intersect with one another at a collision point, wherein at least one recess (3) is provided at the front end (1B) in which at least two of the channel exits (2A, 2A′) are positioned, wherein [0130] the nozzle body (1) has a flat side (1A), with the at least two liquid channels (2, 2′) being entrenched with a defined depth (D) on said flat side (1A), wherein further, a lid (4) is provided that covers the at least two channels (2, 2′), and which has a front end (4B) that is, in a view perpendicular to a longitudinal axis (X) of the nozzle body (1), congruent with the front end (1B) of the nozzle body (1), and wherein [0131] said recess (3) has a first depth (D′) which is larger than the depth (D) of said at least two channels (2, 2′). [0132] 2. Nozzle according to item 1, wherein at least two recesses (3) are provided, and wherein in each of the two recesses only one channel exit (2A, 2A′) is located. [0133] 3. Nozzle according to item 1 or 2, wherein the nozzle body (1) is a monolithic structure. [0134] 4. Nozzle according to any of the preceding items, wherein the recess (3) further has a portion (3′) which extends into the lid (4). [0135] 5. Nozzle according to any of the preceding items, wherein said recess (3) has, seen along longitudinal axis (X), an increasing depth (D′) and/or width (W′), such that a sloping cross section is provided, being widest at the front end (1B, 4B). [0136] 6. Nozzle according to any of the preceding items, comprising a plurality of nozzle bodies (1). [0137] 7. Nozzle according to item 6, wherein each nozzle body (1) has its own recess (3). [0138] 8. Nozzle according to item 6, wherein multiple nozzle bodies (1) share a common recess (3). [0139] 9. Nozzle according to any of the preceding items, wherein a side opposite to the flat side (1A) of one nozzle body (1) serves as lid (4) for an adjoining nozzle body (1). [0140] 10. Nozzle according to any one of items 4 to 9, wherein the lid (4) provides the upper portion (3′) of the recess (3,) and wherein said portion (3′) runs from one side of the lid (4) to the other side. [0141] 11. Nozzle according to item 10, wherein the recess portion (3′) has the shape of a chamfer, with a channel-adjoining edge (6). [0142] 12. Method for the fabrication of a nozzle according to any of the preceding items, the method comprising the steps of [0143] a) providing a nozzle body (1) which has a front end (1B) and which comprises at least two ejection channels (2, 2′), each channel (2, 2′) having an channel exit (2A, 2A′), wherein the ejection channels (2, 2′) are arranged such as to eject liquid along respective ejection trajectories which intersect with one another at a collision point, wherein at least one recess (3) is provided at the front end (1B) in which at least two of the channel exits (2A, 2A′) are positioned, wherein the nozzle body (1) has a flat side (1A), with the at least two liquid channels (2, 2′) being entrenched with a defined depth (D) on said flat side (1A), comprising the following steps: [0144] providing a wafer substrate; [0145] fabricating on one side (1A) of said substrate at least two liquid channels (2, 2′), said channels (2, 2′) having a defined depth (D); [0146] fabricating a recess (3) with a first depth (D′) which is larger than the depth (D) of said at least two liquid channels (2, 2′) in said one side (1A) of the body (1), said recess covering an end portion of the channels (2, 2′); [0147] separating said body (1) from the substrate along a separation line (5) which crosses said recess (3); [0148] such that at least two channel exits (2B, 2B′) in said recess (3) are obtained, wherein the distance between said channel exits (2A, 2A′) remains unaffected by a possible angular or linear deviation of said separation line (5) from an optimal separation line (5′), and [0149] b) covering said nozzle body (1) with a lid (4). [0150] 13. Method according to item 12, wherein the lid (4) covers the at least two channels (2, 2′), and which has a front end (4B) that is, in a view perpendicular to a longitudinal axis (X) of the nozzle body (1), congruent with the front end (1B) of the nozzle body (1). [0151] 14. Method according to item 12 or 13, wherein a pattern representing a plurality of nozzle bodies (1) is batch fabricated in said wafer substrate, and wherein the separation line (5) crosses all recesses (3). [0152] 15. Method according to any one of items 12 to 14, wherein the nozzle is batch-fabricated from a wafer substrate. [0153] 16. Method according to any one of items 12 to 15, wherein the wafer substrate comprises or consists of a brittle material such as silicon, glass, or ceramics. [0154] 17. Method according to any one of items 12 to 15, wherein the wafer substrate comprises or consists of polyether ether ketone (PEEK). [0155] 18. Nozzle according to any one of items 1 to 11, wherein the nozzle is batch-fabricated from a wafer substrate. [0156] 19. Nozzle according to any one of items 1 to 11 or 18, wherein the wafer substrate comprises or consists of a brittle material such as silicon, glass, or ceramics. [0157] 20. Nozzle according to any one of items 1 to 11 or 18 to 19, wherein the wafer substrate comprises or consists of polyether ether ketone (PEEK). [0158] 21. Nozzle according to any of items 1 to 11 or 18 to 20, obtained or obtainable by a process according to any one of claims 12 to 17. [0159] 22. Use of a nozzle according to any of items 1 to 11 or 18 to 21 in an inhalation device for nebulizing a liquid into a respirable aerosol. [0160] 23. Inhalation device for nebulizing a liquid into a respirable aerosol, comprising a nozzle according to any of items 1 to 11 or 18 to 21.

LIST OF REFERENCES

[0161] 1 nozzle body [0162] 1A flat side [0163] 1B front end [0164] 1C front end comprising region [0165] 2, 2′ ejection channel, liquid channel, channel [0166] 2A, 2A′ channel exit [0167] 2B, 2B′ front end channel exit [0168] 3 recess [0169] 3′ upper portion of recess [0170] 4 lid [0171] 4B front end [0172] 5 separation line [0173] 5′ optimal separation line [0174] 6 edge [0175] D depth [0176] D′ depth [0177] W′ width [0178] A, A′ jet axis [0179] X longitudinal axis [0180] Y, Y′ lateral distance [0181] O1, O2 offset [0182] α angle [0183] P plane